Lamp base



FIG. is a perspective view of the lamp base comprising my new design, the the lamp base being symmetric about its vertical axis;

FIG. 2 is an elevational view of my lamp base design;

FIG. 3 is a top plan view of my lamp base design; and,

FIG. 4 is a perspective view of an alternative embodiment of my lamp base design as claimed the only difference being the translucent appearance of the surface.

The broken lines shown in FIGS. 1, 2 and 4 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a lamp base, as shown and described. 